1 Let's take a look at the journey of a stream from beginning to end. It's an interesting story.2 A stream begins high in the mountains. The land is steep. When there is rainfall, or during the spring thaw, water begins to run down the slopes. Soon a channel is carved into the bedrock. A stream is formed. It becomes part of a stream system.3 A stream is ordered by its place in the system. A first order stream has no tributaries. This is the beginning of stream formation. At this point it is small and shallow. It is flowing down a steep slope.4 Soon the stream joins another first order stream to form a second order stream. It begins to widen and deepen. The slope is not quite as steep at this point. But the water is still moving quickly.